Sunday, May 20, 2012

Portable Energy - from fire sticks to lithium

Last night there was a knock on my door at 3am, the flatmate wanted a flame to light his cigarette. We seem to have forgotten how to make fire without help. I have been reading Triumph of the nomadsby Geoffrey Blainey. It has some interesting cultural facts regarding knowledge of energy generation.
Aboriginal fire sticks , the methods of fire making.

Pulling stick over bark, fire plough or fire saw

The bow-drill

The percussion method with pyrites

From fire as source of energy and light we have moved on to more chemical mean, emphasizing on coal, potassium, phosphorus and sulphur. Energy currencies like adenosine tri-phosphate which our own cells prefer to use. I collected a lot of matchboxes while I was young and yesterday the TV was filled with imges of David Beckham and James Bond carrying the Olympic torch across the British Isle. We simply cannot afford to forget how fire is made or let all the fire in our immediate vicinity go out.

Then things switched over to fire steel - ferrocerium and butane, petroleum derivatives. It is still our highest energy density power source being used in most mobile power hungry equipment. Next came the more metallic solid state power sources, burning without visible flames, quietly without explosions unless overheated in certain laptops.

Battery technology has gone through several generations - lemon battery, copper-zinc, zinc-carbon, NiCad, NiMH, Fuel cells, Vanadium Pentoxide, Silver oxide, Lithium and CSIRO made some headway into ultra-batteries by coupling super-capacitors to conventional chemical reaction systems. All involve chemistry and pushing ions up and down electrical staircases to store up energy around the nucleus. With our highly connected life-styles we are plagued by nomophobia, recharge mania. Sometimes I remember the sky is the ultimate device and carry around solar cells to transfer energy from the sky device.

We are constantly pushing electrons downhill in an effort to climb out of this gravity well of a planet we call home. Our techniques to harvest energy so far are not good enough to give us a ticket out without destroying a fair amount of our civilisation in the process. We will have to come up with something ratherdrastic to get out of this bind, pseudoscience or not.